Puget Sound Energy transmission line project

Tukwila underground 115 kV cable replacement project

2018 project updates

Project overview

Customers in the Tukwila area will see continued electric reliability with Puget Sound Energy's planned replacement of the existing 115 kilovolt underground transmission cable. The cable connects the Nelson cable station on West Valley Road in Tukwila, Southcenter substation on Southcenter Parkway in Tukwila, and Tukwila cable substation on S. 168th St. in SeaTac.

The original underground cable was installed in 1974 (see photos of original installation below), with technology that provided an average cable life of 35-45 years. The existing cable is nearing the end of its useful life and is at an increased risk of failure. Today's cable is expected to last 75-100 years due to improvements in insulation materials and manufacturing techniques. Replacing the existing cable will enable PSE to provide continued reliability to customers in the Tukwila area now and well into the future.